Strain-Enhanced Formation of Delocalized Exciton States in Phthalocyanine Crystalline Thin Films

The formation of delocalized excitonic states in organic semiconductors is highly desirable because it leads to efficient energy transport in devices. We investigate the potential of uniaxial strain as a “tuning dial” for delocalized excitons (i.e., exciton–polarons) in crystalline thin films of soluble octabutoxy phthalocyanine. Absorption and photoluminescence spectra confirm the formation of delocalized excitonic states in the presence of tensile strain, accompanied by a red shift of low-frequency vibration modes (–1) in Raman spectroscopy, which are likely responsible for the delocalized exciton formation. Remarkably, an 80% enhancement in photoluminescence intensity and a 30 nm red shift in peak wavelength are observed for a tensile strain of 4.9%, which is equivalent to a temperature reduction approximately by 100 K below room temperature. These results show promise that strain engineering can efficiently modify the exciton–phonon coupling in octabutoxy phthalocyanine crystalline thin films toward enabling delocalization at room temperature

Transition Dipole Moments of One-Dimensional Excitons in Soluble Phthalocyanine Thin Films

We report on polarization-resolved absorption and photoluminescence spectroscopy experiments that investigate the spatial orientation of excitonic transition dipoles at temperatures ranging from 4 K to room temperature in crystalline phthalocyanine thin films prepared with solution-based deposition methods. Octabutoxy phthalocyanines are quasi-1D systems with highly directional intermolecular interactions along a preferred crystalline axis. Experiments reveal the existence of redshifted delocalized bulk band gap exciton states at temperatures below 175 K. These states are the result of the strong π–π short-range coupling and long-range Coulomb coupling between nearest-neighbor molecules along the stacking axis. They are characterized by linearly polarized, nondegenerate dipoles that largely obey the Davydov selection rules. Photoluminescence studies reveal that these excitons couple to lattice and molecular vibrations, forming delocalized exciton-polarons at temperature below 175 K. Finally, by changing the incident light wave vector orientation, we find additional circularly and elliptically polarized states that most likely result from the mixing of HOMO-n (n > 1) orbitals with aza-nitrogen orbitals

Replication and virulence of H5N1 influenza viruses in mice.

<p>(A) Weight changes of mice inoculated with different H5N1 viruses. Groups of five mice were intranasally inoculated with 10⁶ EID₅₀ (50 µL) or with PBS as a control and weighed daily for 14 days. (B) Survival percentage of mice inoculated with H5N1 viruses.</p

Phylogenetic trees for the HA (A), NA (B), and PA (C) genes of the H5N1 influenza A viruses analyzed.

<p>The trees were generated by using CLUSTALx1.83 and MEGA4.0 software by the NJ method (Bootstrap test:1000 replicates, seed = 64238 ) on the basis of the following gene sequences: nucleotides 29–1,695 (1,667 bp) of HA, 21–1,358 (1,338 bp) of NA, and 25–2,163 (2,139 bp) of PA. The length of each pair of branches represents the distance between the sequence pairs, and the units at the bottom of the tree indicate the number of substitution events. The 15 H5N1 isolates from Vietnam are marked in bold italic. Abbreviations: CK, chicken; DK, duck; MDK, Muscovy duck; QL, quail; GS, goose; GD, Guangdong; GX, Guangxi; HK, Hong Kong; VN, Vietnam; SX, Shanxi.</p

Influenza virus isolates from poultry in Vietnam, 2006–2007.

*<p>MDK, Muscovy duck; CK, chicken; DK, duck; VN, Vietnam.</p>†<p>The letters S and N denote southern Vietnam and northern Vietnam, respectively.</p>‡<p>Based on the World Health Organization influenza (H5N1) nomenclature system.</p

Replication and virulence of H5N1 viruses in mice.^a.

a<p>Six-week-old BALB/c mice were used for this study.</p>b<p>Standard deviation.</p>c<p>The data were acquired when mice were inoculated intranasally with 10⁶ EID₅₀ of H5N1 virus in a volume of 50 µL.</p>d<p>The titer shown are the means ± standard deviations of the mice inoculated.</p>e<p>+, Viruses were only detected from undiluted samples; -, the viruses were not detected in the organs.</p>f<p>The data were not acquired.</p

Genotypic evolution of H5N1 viruses isolated from poultry in Vietnam in 2006 and 2007.

<p>The eight gene segments are indicated at the top of each bar. The number in each bar shows the group of genes indicated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050959#pone-0050959-g001" target="_blank">Figure 1</a>. DK/VN208/05 was used in this analysis because it represents the earliest clade 2.3.4 isolate in Vietnam in the public databases to date. † The letters S and N denote southern Vietnam and northern Vietnam, respectively.</p

Image_1_Dysregulation of Ketone Body Metabolism Is Associated With Poor Prognosis for Clear Cell Renal Cell Carcinoma Patients.TIF

Kidney is an important organ for ketone body metabolism. However, the role of abnormal ketone metabolism and its possible function in tumorigenesis of clear cell renal cell carcinoma (ccRCC) have not yet been elucidated. Three differentially expressed key enzymes involved in ketone body metabolism, ACAT1, BDH2, and HMGCL, were screened out between ccRCC and normal kidney tissues using the GEO and TCGA databases.We confirmed that the transcription and protein expression of ACAT1, BDH2, and HMGCL were significantly lower in ccRCC by real-time RT-PCR and IHC assays. Those patients with lower expression of these three genes have a worse outcome. In addition, we demonstrated that ectopic expression of each of these genes inhibited the proliferation of ccRCC cells. The overexpressed ACAT1 and BDH2 genes remarkably impeded the migratory and invasive capacity of ccRCC cells. Furthermore, exogenous β-hydroxybutyrate suppressed the growth of ccRCC cells in vitro in a dose-dependent manner. Our findings suggest that ACAT1, BDH2, and HMGCL are potential tumor suppressor genes, and constitute effective prognostic biomarkers for ccRCC. Ketone body metabolism might thus be a promising target in a process for developing novel therapeutic approaches to treat ccRCC.</p

Data_Sheet_1_RAP44 phage integrase-guided 50K genomic island integration in Riemerella anatipestifer.XLSX

Bacteriophages are viruses that infect bacteria. Bacteria and bacteriophages have been fighting for survival. Over time, the evolution of both populations has been affected. Pathogenic Flavobacteriaceae species including Riemerella anatipestifer mainly infects ducklings, geese, and turkeys. However, it does not infect humans, rats, or other mammals, and is a suitable and safe research object in the laboratory. Our previous study showed that there is a 10K genomic island in R. anatipestiferIn this study, we found another integrated 50K genomic islands and focused on the relationship between R. anatipestifer genomic islands and the RAP44 phage genome. The phage RAP44 genome was integrated into R. anatipestifer chromosome, and an evolutionary relationship was evident between them in our comparative analysis. Furthermore, the integrated defective RAP44 phage sequence had the function of integration, excision, and cyclization automatically. Integrases are important integration elements. The integrative function of integrase was verified in R. anatipestifer. The integrase with the attP site can be integrated stably at the attB locus of the R. anatipestifer genome. A recombinant strain can stably inherit and express the exogenous gene. By studying the integration between host bacterium and phage, we have provided evidence for the evolution of the genomes in R. anatipestifer.</p

Table_1_Dysregulation of Ketone Body Metabolism Is Associated With Poor Prognosis for Clear Cell Renal Cell Carcinoma Patients.DOCX

Kidney is an important organ for ketone body metabolism. However, the role of abnormal ketone metabolism and its possible function in tumorigenesis of clear cell renal cell carcinoma (ccRCC) have not yet been elucidated. Three differentially expressed key enzymes involved in ketone body metabolism, ACAT1, BDH2, and HMGCL, were screened out between ccRCC and normal kidney tissues using the GEO and TCGA databases.We confirmed that the transcription and protein expression of ACAT1, BDH2, and HMGCL were significantly lower in ccRCC by real-time RT-PCR and IHC assays. Those patients with lower expression of these three genes have a worse outcome. In addition, we demonstrated that ectopic expression of each of these genes inhibited the proliferation of ccRCC cells. The overexpressed ACAT1 and BDH2 genes remarkably impeded the migratory and invasive capacity of ccRCC cells. Furthermore, exogenous β-hydroxybutyrate suppressed the growth of ccRCC cells in vitro in a dose-dependent manner. Our findings suggest that ACAT1, BDH2, and HMGCL are potential tumor suppressor genes, and constitute effective prognostic biomarkers for ccRCC. Ketone body metabolism might thus be a promising target in a process for developing novel therapeutic approaches to treat ccRCC.</p